• Toxicological Research
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• v.18 no.2
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• pp.205-213
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• 2002

This study was undertaken to develop a subacute murine model for predicting occurrence of systemic anaphylaxis and to evaluate efficacy of various immunological parameters as the monitoring indices for the occurrence of anaphyalxis. The murine anaphyalxis model was developed through intraperitoneally sensitizing 100 $\mu\textrm{g}$ ovalbumin (OVA) in the presence of 1 mg alum and 300 ng cholera toxin twice a week interval followed by challenging 500 $\mu\textrm{g}$. OVA intravenously. Typical anaphylaxis symptoms were demonstrated at the both BALB/c mice, a strain prone to type-2 response, and C57BL/6 mice. a strain prone to type-1 response. Level of plasma histamine was approximately 50-fold or 30-fold higher in the mice sensitized with OVA than the mice sensitized with alum plus cholera toxin or the saline-treated mice after OVA challenge, respectively. Sensitization and challenge with OVA significantly enhanced plasma leukotriene $B_4$ level but not IgE levels in comparison with the control mice, which indicated the role of leukotriene $B_4$ for progression of anaphyalxis. Furthermore, among mice suffered from anaphylaxis, levels of OVA-specific IgGl were significantly higher in the BALB/c mice than in the C57BL/6 mice, which implied the genetic susceptibility for the induction of systemic anaphylaxis. Conclusively, simultaneous evaluation of histamine, leukotriene $B_4$, and allergen-specific IgG isotype may serve as more efficient monitoring tool for vaccine-related anaphyalxis.

• Molecular & Cellular Toxicology
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• v.2 no.2
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• pp.141-149
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• 2006

Tamoxifen (TAM), a non-steroidal anti estrogen anticancer drug and chemopreventive agent for breast cancer, have caused cholestasis in liver. The potent hepatocarcinogenicity of this drug has been reported. Methotrexate (MTX) is dihydrofolate reductase inhibitor which interfaces with the synthesis for urine nucleotide and dTMP. And it may cause atrophy, necrosis and steatosis in liver. These two anticancer drug have well-known hepatotoxicity. So, in this study we compare the gene expression pattern of antitumor agent TAM and MTX, using the cDNA microarray. We have used 4.8 K cDNA microarray to identify hepatotoxicity-related genes in 5-week-old male Sprague-Dawley (SD) rats. Confirm the pattern of gene expression, we have used Real time PCR for targeted gene. In the case of MTX, Protease related gene (Ctse, Ctsk) and Protein kinase (Pctk 1) have shown specific expression pattern. And in the case of TAM, apoptosis related gene (Pdcd 8) and signal transduction related gene (kdr) have significantly up regulated during treatment time. Gene related with growth factor, lipid synthesis, chemokins were significantly changed. From the result of this study, the information about influence of TAM and MTX to hepatoxicity will provide.

• Molecular & Cellular Toxicology
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• v.2 no.2
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• pp.114-119
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• 2006

Benzo[a]pyrene is a representative ecotoxicant in marine environment and a model compound of polycyclic aromatic hydrocarbons, which has an ability to bioaccumulate in aquatic organisms. This study aimed to identify molecular biomarkers suitable for assessing environmental pollution using a microarray technique. We examined the effects of benzo[a]pyrene on gene expressions in the rockfish, Sebastes schlegeli. We constructed the subtractive cDNA library with hepatic RNA from benzo[a]pyrene-exposed and non-exposed control fish. From the library 10,000 candidate clones were selected randomly and cDNA microarray was constructed. We determined benzo[a]pyrene-responsive genes using a high-density microarray. Statistical analysis showed that approximately 400 genes are significantly induced or reduced by benzo[a]pyrene treatment ($2\;{\mu}m$). Especially gene expression changes of 4 candidate clones among the up- or down-regulated genes were investigated in 6, 12 and 24 hr BaP-exposed fish groups. Many methods have been developed to monitor marine environmental status, which depend on quantifying the levels of the toxic components in polluted seawater or on ecological accessing, such as species diversity or richness. However, those methods could not provide information on physiological or genetic changes induced by such environmental stresses. Comparing with the conventional methods, these data will propose that benzo[a]pyrene-responsive genes can be useful for biological risk assessment of polycyclic aromatic hydrocarbons on marine organism at molecular level.

• Molecular & Cellular Toxicology
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• v.2 no.2
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• pp.75-80
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• 2006

Biomarkers identify various stages and interactions on the pathway from exposure to disease. The three categories of biomarkers are those measuring susceptibility, exposure and effect. Susceptibility biomarkers are identifiable genetic variations affecting absorption, metabolism or response to environmental agents. Biomarkers of exposure indicate the amount of a foreign compound that is absorbed into the body. Biological measurements performed on human tissues are vastly expanding the capabilities of classical epidemiology, which has relied primarily on estimates of human exposure derived form chemical levels in the air, water, and other exposure routes. Biomarkers of exposure indicate the amount of a foreign compound that is absorbed into the body. Biological measurements performed on human tissues are vastly expanding the capabilities of classical epidemiology, which has relied primarily on estimates of human exposure derived form chemical levels in the air, water, and other exposure routes. The biomarker response is typical of chemical pollution by specific classes of compound, such as (i) heavy metals (mercury, cadmium, lead, zinc), responsible for the induction of metallothionein synthesis, and (ii) organochlorinated pollutants (PCBs, dioxins, DDT congeners) and polycyclic aromatic hydrocarbons (PAHs), which induce the mixed function oxygenase (MFO) involved in their bio transformations and elimination. Currently genomic researches are developed in human cDNA clone subarrays oriented toward the expression of genes involved in responses to xenobiotic metabolizing enzymes, cell cycle components, oncogenes, tumor suppressor genes, DNA repair genes, estrogen-responsive genes, oxidative stress genes, and genes known to be involved in apoptotic cell death. Several research laboratories in Korea for kicking off these Environmental Genomics were summarized.

• Molecular & Cellular Toxicology
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• v.1 no.2
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• pp.111-115
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• 2005

Ultraviolet (UV) radiation to mammalian skin is known to alter cellular function via generation of Reactive Oxygen Species (ROS), DNA damage and DNA lesions, such as pyrimidine dimmers and photoproducts, which could lead to DNA mutation if they are not repaired. In this study, we have investigated the reduction of DNA damage and of apoptosis with a particular attention to genetic effect of paeoniflorin in Normal Human Epidermal Keratinocytes (NHEK). After UVB irradiation from $10\;to\;500mJ/cm^{2}$ to NHEK, Mean Tail Moments (MTM) were increased with UVB dose increase. The greatest amount of strand breaks was induced at $500mJ/cm^{2}$ of UVB. Even at the lowest dose of UVB ($10mJ/cm^{2}$), change in MTM was detected (P<0.0001). Pretreated cell with 0.1% paeoniflorin maximally reduced the level of DNA damage to about 21.3%, compared to untreated cell. In the lower concentrations less than 0.01% of paeoniflorin, MTM had a small increase but paeoniflorin still had reductive effects of DNA damage. We measured the apoptosis suppression of paeoniflorin with annexin V flous staining kit. As we observed under the fluorescence microscopy to detect apoptosis in the irradiated cell, the fluorescence intensity was clearly increased in the untreated cell, but decreased in treated cells with paeoniflorin. These results suggest that paeoniflorin reduces the alteration of cell membranes and prevents DNA damage. Therefore, the use of paeoniflorin as a free radical scavenger to reduce the harmful effects of UV lights such as chronic skin damage, wrinkling and skin cancer can be useful to prevent the formation of photooxidants that result in radical damage.

• Molecular & Cellular Toxicology
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• v.5 no.4
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• pp.346-353
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• 2009

Drug metabolism is a critical determinant of the therapeutic and adverse effects of many psychotropic drugs. The metabolism depends on the pharmacokinetics of a drug, which includes its absorption, distribution, and elimination. Psychotropic drugs are metabolized mainly by cytochrome P450 (CYP) enzymes; about 20 of these enzymes exist and they are often responsible for the rate-limiting step of drug metabolism. CYP2D6 is the best-characterized P450 enzyme that exhibits polymorphism in humans. This study determined the relationship between the CYP2D6*10 (P34S) polymorphism and the response to mirtazapine in 153 Koreans with major depressive disorder (MDD). The genotype frequencies were compared using logistic regression analysis, and between-genotype differences in the decrease in the 21-item Hamilton Depression (HAMD21) score over the 12-week treatment period were analyzed using a linear regression analysis. The proportion of remitters was lower in patients with MDD possessing the S allele than in P allele carriers after 2 weeks of mirtazapine treatment. Similarly, the reductions in the HAMD21 and Clinical Global Impression (CGI) scores in S allele carriers were smaller than those in patients with the P allele after 2 weeks of mirtazapine treatment. In the analysis of depression symptoms, the sleep and delusion scores had smaller reductions in S allele carriers. Based on the Liverpool University Neuroleptic Side Effect Rating Scale (LUNSERS), the psychic adverse effects of mirtazapine were associated with CYP2D6 P34S, while weight gain was not. These results suggest that CYP2D6 P34S affects the outcome of mirtazapine treatment in patients with MDD, and that this polymorphism may be a good genetic marker for predicting the clinical outcome of mirtazapine treatment.

• Molecular & Cellular Toxicology
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• v.5 no.2
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• pp.160-164
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• 2009

Notch signaling plays a crucial role in development of the nervous system. Neurodevelopmental hypothesis on etiology of schizophrenia has been implicated. The aim of this study is to determine whether single nucleotide polymorphisms (SNPs) of Notch homolog 4 (Drosophila) (NOTCH4) gene are associated with schizophrenia. This study included 283 schizophrenia patients diagnosed according to DSM-IV and 301 normal control subjects. Control subjects without history of psychiatric disorders were recruited. Four missense SNPs [rs915894 (exon 3, Lys117Gln), rs2071282 (exon 4, Pro204Leu), rs422951 (exon 6, Thr320Ala), and rs17604492 (exon 18, Gly942Arg)] of NOTCH4 gene were genotyped by the direct sequencing method. Multiple logistic regression models (codominant, dominant, and recessive models) were employed to evaluate odds ratio, 95% confidence interval, and p value. For analysis of genetic data, SNPStats, Haploview, HapAnalyzer, SNPAnalyzer, and Helixtree programs were also used. Of 4 SNPs, rs2071282 was weekly associated with schizophrenia in two alternative models (codominant model, P=0.049; dominant, P=0.041). However, these associations were not significant after Bonferroni correction. At 4 SNPs, one linkage disequilibrium (LD) block was made. This block consisted of rs915894 and rs2071282. In haplotype analysis, AC haplotype was weakly associated with schizophrenia (dominant, P=0.04). This association was disappeared after Bonferroni correction. Our result shows possibility that some SNPs of NOTCH4 gene may be weekly associated with development of schizophrenia in Korean population. However, replication result by other population will be needed.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7149-7152
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• 2014

A large number of epidemiological studies have demonstrated that obesity is a risk factor for several human cancers. Several animal studies using rodents with diet-induced or genetic obesity have also demonstrated that obesity can promote tumor development. However, the effects of obesity on the early stages of carcinogenesis, and especially on the spontaneous occurrence of somatic gene mutations, remain unclear. To investigate the effects of obesity on the rate of spontaneous gene mutations, we performed reporter gene mutation assays in liver, kidney, and colon, organs in which obesity appears to be associated with cancer development on the basis of epidemiological or animal studies, in mice with high fat diet (HFD)-induced obesity. Six-week-old male and female C57BL/6 gpt delta mice were fed HFD or standard diet (STD) for 13 or 26 weeks. At the end of the experiments, reporter gene mutation assays of liver, kidney, and colon were performed. Final body weights and serum leptin levels of male and female mice fed HFD for 13 or 26 weeks were significantly increased compared with corresponding STD-fed groups. Reporter gene mutation assays of liver, kidney, and colon revealed that there were no significant differences in gpt or $Spi^-$ mutant frequencies between STD- and HFD-fed mice in either the 13-week or 26-week groups. These results indicate that HFD treatment and consequent obesity does not appear to influence the spontaneous occurrence of somatic gene mutations.

• Toxicological Research
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• v.31 no.1
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• pp.17-23
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• 2015

Excessive manganese (Mn) in the brain promotes a variety of abnormal behaviors, including memory deficits, decreased motor skills and psychotic behavior resembling Parkinson's disease. Hereditary hemochromatosis (HH) is a prevalent genetic iron overload disorder worldwide. Dysfunction in HFE gene is the major cause of HH. Our previous study has demonstrated that olfactory Mn uptake is altered by HFE deficiency, suggesting that loss of HFE function could alter manganese-associated neurotoxicity. To test this hypothesis, Hfe-knockout ($Hfe^{-/-}$) and wild-type ($Hfe^{+/+}$) mice were intranasally-instilled with manganese chloride ($MnCl_2$ 5 mg/kg) or water daily for 3 weeks and examined for memory function. Olfactory Mn diminished both short-term recognition and spatial memory in $Hfe^{+/+}$ mice, as examined by novel object recognition task and Barnes maze test, respectively. Interestingly, $Hfe^{-/-}$ mice did not show impaired recognition memory caused by Mn exposure, suggesting a potential protective effect of Hfe deficiency against Mn-induced memory deficits. Since many of the neurotoxic effects of manganese are thought to result from increased oxidative stress, we quantified activities of anti-oxidant enzymes in the prefrontal cortex (PFC). Mn instillation decreased superoxide dismutase 1 (SOD1) activity in $Hfe^{+/+}$ mice, but not in $Hfe^{-/-}$ mice. In addition, Hfe deficiency up-regulated SOD1 and glutathione peroxidase activities. These results suggest a beneficial role of Hfe deficiency in attenuating Mn-induced oxidative stress in the PFC. Furthermore, Mn exposure reduced nicotinic acetylcholine receptor levels in the PFC, indicating that blunted acetylcholine signaling could contribute to impaired memory associated with intranasal manganese. Together, our model suggests that disrupted cholinergic system in the brain is involved in airborne Mn-induced memory deficits and loss of HFE function could in part prevent memory loss via a potential up-regulation of anti-oxidant enzymes in the PFC.

• Toxicological Research
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• v.23 no.3
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• pp.245-251
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• 2007

Water extract of Cordyceps militaris grown upon Protuetja dreujtarsis (CMPD) was examined for the genetic toxicity-bacterial mutagenicity, chromosome aberration, and micronucleus formation. For mutagenicity assay, bacterial reversion test with Salmonella typhimurium TA98, TA100, TA1535, TA 1537, and E. coli WP2uvrA were performed. The extract at the concentrations of $50{\sim}5,000{\mu}g/plate$ did not induce mutagenicity at all. Chromosome aberration test was performed by using Chinese lung (CHL) cells. There was no significant chromosome aberration in CHL cells with S-9 mixture at the concentrations of $312.5{\sim}1,250{\mu}g/ml$ of the extract and without S-9 mixture at the concentrations of $1.2{\sim}19.5{\mu}g/ml$ of the extract. For micronucleus test, ICR mice were treated with the extract at the dose of 0.5, 1, and 2g/Kg. The frequencies of the micronucleated polychromatic erythrocytes (MNPCE) in bone marrow preparations of the extract-treated group were not increased compared to the untreated control group. Taken together, our results show that water extract of CMPD did not induce any harmful genotoxicity.